1. Field of the Invention
This invention relates to a pen nib construction, comprising a pen nib and its holder, which is easy to manufacture and almost free from clogging.
2. Description of the Prior Art
Conventional pens with a single-piece pen nib have the disadvantage that they write only in a certain direction. To obviate the disadvantage, a pen nib construction has been provided, which comprises a plurality of (three, for instance) pen nib pieces, similar to conventional pen nibs, that are fixed back to back to each other so as to make it possible to write in all directions.
In spite of its advantage that it writes in any direction without turning the pen, the aforesaid pen nib construction has been found to have at least the following two disadvantages.
One is that the pen nib construction is not suitable for mass production because it is difficult to assemble, although some improvements in the process of manufacture have been provided (as found in Japanese Utility Model Application No. 009544/1979).
The other is that an ink channel in the pen nib construction is liable to be clogged with fine pieces of paper which have been removed by the pointed end of the pen nib and brought into the ink channel. In this case, if the pen remains unused for a long period of time, it will not write at all.
The pen nib construction of the prior art is shown in FIGS. 1 to 6. A pen nib 5 (FIG. 2) in the pen nib construction has been made as follows. First, three (or more than three) pen nib pieces 1, each having a split 3 at its pointed end and another split 21 at its root, are made by stamping, etc. Next, each of the pen nib pieces 1 is bent either square along bending lines 2 or round by pressing, etc. Then, the pen nib pieces 1 are fixed back to back to each other by cementing, spot welding or other means. Japanese Utility Model Application No. 009544/1979 discloses in detail an improved process for making the pen nib 5, in which process one pen nib plate consisting of three (or more than three) continuous pen nib portions is stamped out, and is made into a pen nib by means of a press, etc.
FIGS. 3 and 4 are enlarged schematic views showing the cross sections near the root and pointed end of the pen nib 5 made by either of the aforesaid processes. FIG. 4 is enlarged in a larger ratio than FIG. 3. As seen from these figures, the pen nib 5 has three concaves 6 and three projections 22 disposed alternately along its outside, and is provide in the center with an ink channel 7 for feeding ink from an ink reservoir of the pen to the pointed end of the pen nib. Each of the pen nib pieces 1 (or pen nib portions) is provided with the split 3 at its pointed end and also with notches 4 at its both edges as shown in FIG. 1a. Therefore, the pen nib 5 is provided at its pointed end with three splits 3 and three chinks 8 formed by the notches 4, which are disposed alternately and at equal angular distances as shown in FIG. 4. Inside said ink channel 7, an ink feed needle 10, a little smaller in diameter than the ink channel 7, is fixed for feeding ink to the pointed end of the pen nib 5.
The pen nib 5 is fitted in a holder 12 of synthetic resin, etc. separately made by molding, etc. One end of the holder 12 is substantially equally divided into three ink feed tongues 19. When the pen nib 5 is inserted into the holder 12, the inner surface of each ink feed tongue 19 elastically contacts each concave 6 of the pen nib 5 so that the pen nib 5 is held in the holder 12. The holder 12 containing the pen nib 5 is fitted in the barrel of the pen.
Experiments performed by the inventor have proved that the two disadvantages of the prior art mentioned above are attributable to the composition of the pen nib construction. As obvious from FIG. 3, the pen nib pieces 1 are bent so that the ink channel 7 has a relatively large cross sectional area, and therefore the ink feed needle 10 inserted therein must be relatively thick. To feed ink effectively, the ink feed needle 10 usually consists of wire strands, not a single wire. It is very difficult to insert such a needle of wire strands into the ink channel 7, and this seriously decreases the efficiency of assembly work. In addition, the supply of ink to the pointed end of the pen nib 5 is performed only through the ink channel 7 provided in the center. Therefore, if paper fiber sticks in or above an ink containing portion 11 provided inside near the pointed end of the pen nib 5, the pen is clogged and ink does not flow down to the pointed end of the pen nib 5.